While Samsung and Nokia (and everyone else really) are locked in a sort of mobile photography war by baking elaborate cameras into new smartphones, Sony is apparently testing a slightly different approach. Rather than cramming a high-end camera into a phone, the folks at SonyAlphaRumors have happened upon a set of photos that depict a pair of Sony “lens cameras” that latch onto your smartphone instead.

This isn’t the first time Sony’s curious camera phone attachments have popped up — they were the subject of another leak earlier this year — but now we’ve got a clearer picture of what these things are actually capable of. At first glance, the hefty things don’t seem too different from some other smartphone accoutrements out there right now, but their looks are deceiving.

See, the attachments don’t actually augment your phone’s built-in camera so much as they replace them entirely. That’s the weird thing about what Sony has cooked up: They’re more than just a lens, but they’re not quite a standalone camera, either. Instead, the devices float in the limbo between both of those things and relies wholly on a smartphone to actually make it usable. According to the SonyAlphaRumors’ report, everything — from the 18- or 20-megapixel sensor to the image processor to the SD card slot — is packed into those barrels while the phone it’s connected to acts as the viewfinder.

For what it’s worth, Sony’s rationale seems at least partially defensible. So long as companies like Samsung, Apple, HTC, and even Sony want to duke it out over how thin they can make their smartphones, they also need to figure out how to continuously improve those mobile cameras while keeping heft to a minimum (unless they temporarily lose their minds). By moving the lion’s share of the hardware outside of the chassis completely, Sony gets to continue trying to push the envelope on camera performance without having to worry about the impact all that extra hardware has on the aesthetics of a new phone. And since these lens cameras aren’t tied into one specific device, Sony could see continued sales of the things even after consumers ditch their old phones for new ones. It’s definitely a strange approach, but it’s also pretty smart.

As we all know, though, being smart doesn’t necessarily translate into being successful, and there are plenty of reasons why something like this wouldn’t catch on. You’ve got to carry around another gizmo for one, and the potential price tag could cause would-be mobile photogs to balk (especially when decent point-and-shoots are getting stupidly cheap). It shouldn’t be long before these lens cameras start trickling into the wild, so we’ll soon see if Sony is actually onto something here.